56 lines
1.8 KiB
C
56 lines
1.8 KiB
C
#include "header.h"
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// Table 14-6. Port C Pins Alternate Functions
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// - PC0 -> ADC0 (ADC Input Channel 0)
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// -> PCINT8 (Pin Change Interrupt 8)
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//
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// 24.2 : The ADC generates a 10-bit result which is presented in the ADC Data Registers, ADCH and ADCL
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#define INT_TO_HEX_CHAR(n) ((n) < 10 ? ('0' + (n)) : ('A' + ((n) - 10)))
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void int_to_hex_string(uint64_t value, char *out, uint8_t num_digits) {
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for (uint8_t i = 0; i < num_digits; ++i) {
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uint8_t shift = (num_digits - 1 - i) * 4;
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out[i] = INT_TO_HEX_CHAR((value >> shift) & 0x0F);
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}
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out[num_digits] = '\0';
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}
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void word_to_hex(uint16_t value, char *out) {
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out[0] = INT_TO_HEX_CHAR((value >> 8) & 0x0F);
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out[1] = INT_TO_HEX_CHAR((value >> 4) & 0x0F);
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out[2] = INT_TO_HEX_CHAR(value & 0x0F);
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out[3] = '\0';
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}
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void adc_init() {
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ADMUX = (1 << REFS0); // AVcc reference, ADC0
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ADCSRA = (1 << ADEN) // Enable ADC
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| (1 << ADPS2) | (1 << ADPS1) | (1 << ADPS0); // Prescaler = 128
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}
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uint16_t adc_read(uint8_t channel) {
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ADMUX = (ADMUX & 0xF0) | (channel & 0x0F); // Select ADC channel
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ADCSRA |= (1 << ADSC); // Start conversion
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while (ADCSRA & (1 << ADSC)); // Wait for completion
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return ADC;
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}
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// description
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int main() {
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char buffer[4];
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SREG |= ENABLE_GLOBAL_INTERRUPT; // 7.3.1 : Status Register, bit 7 : I – Global Interrupt Enable
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uart_init();
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adc_init();
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while(1) {
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uint16_t value = adc_read(0); // Read from ADC0 (A0)
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// snprintf(buffer, sizeof(buffer), "ADC: %u\r\n", value);
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word_to_hex(value, buffer);
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uart_printstr(buffer);
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uart_printstr("\r\n");
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_delay_ms(20); // Wait 20ms
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}
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}
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// ISR(ADC_vect) { // Table 12-6 : interrupt vector for ADC Conversion Complete
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// }
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